I'm a professional scale model aircraft builder, and as such, one of the materials I use is balsa wood. I always have plenty of wood shavings, and balsa dust floating around. I was curious if anyone has used balsa wood in their compost pile. I can't think why not, but you never know. I searched all over the net and found nothing on it.
Balsa wood is considered brown in composting. Brown takes longer to decompose and depletes more nitrogen in the process of decomposing. I wouldn't use too much balsa.